Site-directed mutagenesis of Histidine 106 and Lysine 107 residues in the Proteus mirabilis glutathione transferase B1-1

The crystal structure of PmGST B1-1 suggested that one or more residues in the C-terminal domain of the enzyme might stabilise the activated form of g lutathione for conjugation reaction. In order to test this hypothesis we ha ve emulated His 106 and Lys 107 of PmGST B1-1 to investigate their possible role in the enzyme's catalytic activity. The data are consistent with His 106 and Lys 107 bring involved in interacting with glutathione in the site active but these residues do not contribute significantly to catalysis. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.